Dual additive feeder for dishwashing

ABSTRACT

This dual feeder includes a venturi device communicating with a pair of aspirator tubes to draw liquid additives from a pair of independent containers. Depletion of the additive in one container below the intake level of the aspirator tube results in automatic cut-off of the additive in the other container.

United States Patent Holmes et a1.

154] DUAL ADDlTlVE FEEDER FOR DISHWASHING [75] Inventors: LambertHolmes, Creve Coeur;

Franklin M. McDougall, St. Louis, both of Mo.

[73] Assignec: Economical Laboratory, Inc., St.

Paul, Minn.

[22] Filed: Dec. 11, 1970 I21] Appl. No.1 97,127

(52] US. Cl 222/1, 137/604, 222/66, 222/132, 239/318 [51 l Int. Cl B67b7/00 [58] Field of Search 137/604; 222/61, 222/66, 193, 136, 1, 132;417/176, 182.5; 138/44; 239/304, 318

[56] References Cited UNITED STATES PATENTS 2,724,583 11/1955 Targosh eta1. 239/318 X [451 Sept. 4, 1973 2,975,804 3/1961 Dunn et a], 239/318 X3,112,884 12/1963 Gilmour 3,643,688 2/1972 Meinert 2,952,209 9/1960Scholin 3,038,495 6/ 1962 Fortin 3,459,334 8/1969 Evans 222/132 PrimaryExaminer-Samuel F. Coleman Attorney-Cohn & Powell [5 7] ABSTRACT Thisdual feeder includes a venturi device communicating with a pair ofaspirator tubes to draw liquid additives from a pair of independentcontainers. Depletion of the additive in one container below the intakelevel of the aspirator tube results in automatic cut-off of the 1additive in the other container.

6 Claims, 2 Drawing Figures 'i' 14 n a .2 -16 e6 eof l|= 81 //I filo 1ii 1 ,5 52"-\y I DUAL ADDITIVE FEEDER FOR DISHWASHING BACKGROUND OF THEINVENTION This invention relates in general to a dual additive feederfor a dishwashing machine and in particular to a feeder providingautomatic cut-off of both additives supplied by the feeder to adishwashing machine when the supply of one additive is exhausted.

One of the ways in which liquid chemical additives are supplied to adishwashing machine is by use of a venturi-aspirator system in which theliquid additive is sucked into the mainstream of a water supply andtransported to the dishwashing machine. Known devices used to supplymore than one additive appear to operate by one of two methods. Eitherthe additives are mixed together prior to aspiration or alternativelycompletely independent venturi-aspirator systems are provided for eachadditive. The former method suffers from the disadvantage that additivesare often incompatible before mixing with water with the result thatpre-mixing them reduces their storage life. The latter method suffersfrom the disadvantage that when the supply of only one additive isdepleted, the other additive continues to be fed into the dishwashingmachine and is wasted because both additives are required to provide aneffective washing process. These disadvantages are overcome in thepresent invention.

SUMMARY OF THE INVENTION This dual feeder does not require pre-mixing ofthe additives and hence increases the storage life of incompatibleadditives. Further, when the supply of one additive is depleted, thesupply of the other is automatically cut off and thus there is nowastage of the additive not yet depleted.

The dual feeder provides a means of feeding additives from a pair ofadditive reservoirs into the water supply to a dishwashing machine andincludes cut-off means automatically cutting off additive from one ofthe reservoirs when the additive in the other of said reservoirs isexhausted. The feeder means includes a pair of feed lines having intakeports immersible in associated reservoirs, said one reservoirbeing.-;-cut off when the additive in the other reservoir falls belowthe level of its associated aspirator tube intake port.

The dual feeder includes a venturi means receiving the water supply andthe feed lines are provided by aspirator tubes communicating between thethroat of the venturi means and the additive reservoirs so that when thesupply of one additive is depleted to a level below the end of the tube,the vacuum at the venturi throat is broken resulting in automaticcut-off of the additive in the other reservoir.

The venturi means preferably includes two venturis interconnected attheir throat portions by a conduit. Mixing chambers are provided at eachventuri throat and the conduit extends between said mixing chambers.Each aspirator includes an aspirator port communicating directly withthe mixing chambers of an associated venturi so that the aspirators arein communication with each other.

The water supply line includes branch portions, each connected to theentrance of an associated venturi and the discharge line includes acommon mixing chamber communicating with the exit port of each venturi.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the dual feederused in conjunction with a dishwashing machine, and

FIG. 2 is an enlarged sectional view of the mixer block.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring now by characters of reference to the drawing and first toFIG. 1, it will be understood that in the preferred embodiment, the dualadditive feeder, generally indicated by numeral 10, is utilized inconjunction with a dishwashing machine 11 and provides a means ofinjecting at least two dishwashing additives in liquid form into acommon water supply for delivery to said machine 11. The liquidadditives are aspirated from containers l2 and 13 which constitute firstand second reservoirs.

The dual feeder 10 includes a mixer block 14 shown in enlarged detail inFIG. 2 and in which is formed a pair of venturis l5 and 16 constitutingfirst and second venturis. Each venturi includes an entrance port 20, anexit port 21 and a throat portion 22. The throat portion 22 is smallerin' diameter than the entrance and exit ports 20 and 21 to effectuatethe reduction in fluid pressure characteristic of a venturi device. Amixing chamber, generally indicated by numeral 23, is formed about eachventuri throat 22. The mixing chambers 23 are substantially cylindricalin configuration. Each chamber 23 communicates with the upstreamconvergent portion 24 of an associated venturi and also leads directlyinto the downstream divergent portion 25 of said venturi. The mixingchambers 23 are interconnected by a conduit 26 extending between saidchambers 23 and said conduit 26 in effect, provides communicationbetween the throat portions 22 of each of the venturis l5 and 16.

In the preferred embodiment, water is supplied to the mixer block 14 bya supply line 17 connected to a water main 18. The supply line 17communicates by means of a fitting 19 directly to an inlet passage 27 ofthe mixing block 14, said passage 27 communicating in turn with-aninverted U-shaped passage 28 have opposed branch portions 29, eachcommunicating directly with the entrance port 20 of an associatedventuri.

The liquid additives from the containers l2 and 13 are supplied to themixer block 14 by aspirator tubes 30 and 31 respectively. The aspiratortubes 30 and 31 each include an intake port 32 or 33 operativelydisposed below the level of the liquid additive and each of said tubes30 and 31 is connected directly to an associated aspirator passage 34 bymeans of a fitting 35. The combined aspiratortubes andpassagesconstitute aspirator means providing feed lines between the reservoirsl2 and 13 and the venturis l5 and 16 respectively. The aspiratorpassages 34 are formed in mirror-image of each other within the mixerblock 14 and each communicates directly with the mixing chamber 23 of anassociated venturi by means of an aspirator port 36. The ports 36 arepreferably located substantially at the throat portion 22 of anassociated venturi. It will be understood that by virtue of the conduitinterconnecting passage 26, between the mixing chambers 23, theaspirator passages 34 are efi'ectively in communication with each other.

The venturis l5 and 16 discharge into a common discharge line 37 whichincludes a flared collection head 38 disposed within a cylindricalcavity 39 communicating with the exit ports 21 of the venturis l5 and 16and providing a common mixing chamber for additivecharged water issuingfrom each of the venturis. The combined stream charged with bothadditives passes from the collection head 38 into the dishwashingmachine ll as clearly indicated in FIG. 1. The operation of the dualfeeder is such that when either one of the liquid additives is depletedsufficiently so that the level falls below the inlet port of itsassociated aspirator tube, the supply of both additives is automaticallycut off. This operation will now be briefly described.

Water supplied under pressure from the mains 18 passes through the dualventuris and 16 on route to the dishwashing machine 11. During normaloperation, the pressure drop at the venturi throats 22 is sufficient toaspirate liquid additive from each of the containers [2 and 13 intoassociated mixing chambers 23 for mixing with the water stream. However,if the liquid additive in one container, for example in container 13,falls below the elevation of intake port 33 so that the aspirator tube31 is no longer immersed in liquid additive, the vacuum at the throat ofventuri 16 is destroyed. Because the throats 22 of each of the venturisl5 and 16 are in communication, by virtue of the conduit 26, the vacuumat the throat of the venturi 15 is also destroyed and the aspiration ofthe additive from the other container, container 12, automaticallyceases. Thus, wasteful supply of a single additive from the container 12to the dishwashing machine 11 cannot occur. The delivcry of theuncharged water to the dishwasher 11 continues immediately followingadditive cut-off but, because of the cutoff of the supply of bothadditives, this water dilutes the wash solution present in thedishwashing machine 11. A conventional controller (not shown) respondingto the dilution of the wash solution may be provided to make an audibleor visual signal to indicate that replenishment of the additivecontainers is required.

We claim as our invention:

1. A dual additive feeder for a dishwashing machine comprising:

a. a venturi including an entrance port, an exit port and a throatdisposed between said ports,

b. supply means supplying fluid to the entrance port,

c. a first liquid additive reservoir,

d. a first aspirator means communicating between the first additivereservoir and the throat portion of the venturi at one location on thethroat portion,

e. a second liquid additive reservoir,

f. a second aspirator means communicating between the second additivereservoir and the throat portion of the venturi at another location onthe throat portion, the first and second aspirator means aspiratingadditives to the venturi throat under normal operating conditions and,when one additive is depleted to a predetermined level the associatedaspirator means supplying air in lieu of additive to the venturi throatto automatically cut off the other aspirator means, and

g. discharge means discharging fluid from the exit port.

2. A dual additive feeder as defined in claim I, in

which:

h. the venturi includes a mixing chamber peripherally disposed about thethroat portion, and x i. each aspirator means includes an elongate tubecommunicating with the mixing chamber and having a air inlet portdisposed below the additive level under normal operating conditions toaspirate additives to said mixing chamber and both aspirator means beingcut off when the level of one additive falls below the inlet port of theassociated aspirator means.

3. A dual additive feeder for a dishwashing machine,

comprising:

a. a first venturi including an entrance port, an exit port and a throatportion disposed between said ports,

b. a second venturi including an entrance port, an exit port and athroat portion disposed between said ports,

c. conduit means communicating between the throat portions of said firstand second venturis,

d. supply means supplying fluid to the entrance ports of each venturi,

e. a first additive reservoir,

f. a first aspirator means communicating between the first additivereservoir and the throat portion of the first venturi,

g. a second additive reservoir,

h. a second aspirator means communicating between the second additivereservoir and the throat portion of the second venturi,

i. discharge means discharging fluid from the exit ports of the firstand second venturis.

4. A dual additive feeder as defined in claim 3, in which: j. the supplymeans includes a main supply line and a pair of branch portions, eachbranch portion being connected between the main supply line and anassociated venturientrance port, k. the discharge means includes adischarge mixing chamber communicating with the exit ports of theventuris.

5. A dual additive feeder as defined in claim 3, in which: j. a mixingchamber is peripherally disposed about the throat portion of eachventuri, k. the conduit means includes a passage communicating betweenthe mixing chambers, and I. each aspirator means includes an elongatetube communicating with an associated mixing chamber.

6. A method of feeding and cutting off additives in a dishwashing systemcomprising the steps of: a. passing a water supply through a venturi, b.supplying one liquid additive to the throat of the venturi byaspiration, c. supplying another liquid additive to the throat of theventuri by aspiration, d. supplying air to the venturi throatselectively in lieu of one of said liquid additives to destroy theventuri vacuum and automatically terminate the supply of both of saidadditives.

# t i i UNETED ST TES PATENT OFFICE I CE THHCATE 0i eeeieeeimow PatentNo. 3 I 756 r 457 Dated September 4 1973 Inventor(s) LAMBERT HOLMES andFRANKLIN M. McDOUGALL It is certified that 7 error appears in theaboveidentified patent and that said Letters Patent" are herebycorrected as shown below:

In the Title page, the designated Assignee "Economical- Laboratory,Inc.," should read-Economics Laboratory, Inc.

Signed arid saled thie 25th. day of December 1973.

(SEAL) AtteSt:

' EDWARD M.FLETCHEZR,JR. D; v

Attsting Officer Acting Commissioner of Patents a F PO-IOSO (1069)uscowx 0: van be;

1. A dual additive feeder for a dishwashing machine comprising: a. aventuri including an entrance port, an exit port and a throat disposedbetween said ports, b. supply means supplying fluid to the entranceport, c. a first liquid additive reservoir, d. a first aspirator meanscommunicating between the first additive reservoir and the throatportion of the venturi at one location on the throat portion, e. asecond liquid additive reservoir, f. a second aspirator meanscommunicating between the second additive reservoir and the throatportion of the venturi at another location on the throat portion, thefirst and second aspirator means aspirating additives to the venturithroat under normal operating conditions and, when one additive isdepleted to a predetermined level the associated aspirator meanssupplying air in lieu of additive to the venturi throat to automaticallycut off the other aspirator means, and g. discharge means dischargingfluid from the exit port.
 2. A dual additive feeder as defined in claim1, in which: h. the venturi includes a mixing chamber peripherallydisposed about the throat portion, and i. each aspirator means includesan elongate tube communicating with the mixing chamber and having a airinlet port disposed below the additive level under normal operatingconditions to aspirate additives to said mixing chamber and bothaspirator means being cut off when the level of one additive falls belowthe inlet port of the associated aspirator means.
 3. A dual additivefeeder for a dishwashing machine, comprising: a. a first venturiincluding an entrance port, an exit port and a throat portion disposedbetween said ports, b. a second venturi including an entrance port, anexit port and a throat portion disposed between said ports, c. conduitmeans communicating between the throat portions of said first and secondventuris, d. supply means supplying fluid to the entrance ports of eachventuri, e. a first additive reservoir, f. a first aspirator meanscommunicating between the first additive reservoir and the throatportion of the first venturi, g. a second additive reservoir, h. asecond aspirator means communicating betWeen the second additivereservoir and the throat portion of the second venturi, i. dischargemeans discharging fluid from the exit ports of the first and secondventuris.
 4. A dual additive feeder as defined in claim 3, in which: j.the supply means includes a main supply line and a pair of branchportions, each branch portion being connected between the main supplyline and an associated venturi entrance port, k. the discharge meansincludes a discharge mixing chamber communicating with the exit ports ofthe venturis.
 5. A dual additive feeder as defined in claim 3, in which:j. a mixing chamber is peripherally disposed about the throat portion ofeach venturi, k. the conduit means includes a passage communicatingbetween the mixing chambers, and l. each aspirator means includes anelongate tube communicating with an associated mixing chamber.
 6. Amethod of feeding and cutting off additives in a dishwashing systemcomprising the steps of: a. passing a water supply through a venturi, b.supplying one liquid additive to the throat of the venturi byaspiration, c. supplying another liquid additive to the throat of theventuri by aspiration, d. supplying air to the venturi throatselectively in lieu of one of said liquid additives to destroy theventuri vacuum and automatically terminate the supply of both of saidadditives.